A lot of them generate 404s but still it's a very valuable list, thanks!

  -2017-11-26 22:15:18--  http://www.oreilly.com/design/free/files/2016-design-salary-survey-report.epub
  Reusing existing connection to www.oreilly.com:80.
  HTTP request sent, awaiting response... 404 Not Found
  2017-11-26 22:15:18 ERROR 404: Not Found.